A pacing lead for implantation in a coronary sinus having an opening and a wall defining an interior and presenting a diameter dimension. The pacing lead includes an elongated lead body, a resilient fixation element, and at least one electrode on either the lead body or the fixation element. The fixation element extends from the pacing portion and defines a loop structure laterally adjacent the pacing portion. The loop structure presents a predetermined width dimension greater than the diameter dimension of the coronary sinus, wherein when the loop structure is inserted into the opening of the coronary sinus, the loop structure is laterally compressed by the wall of the coronary sinus and the electrode is biased against the wall of the coronary sinus.
|
1. A pacing lead for implantation in a coronary sinus having an opening and a wall defining an interior and presenting a diameter dimension, the pacing lead comprising:
an elongated lead body defining an elongated longitudinal axis; and
a preformed resilient fixation element extending from a distal end of the lead body and defining a loop structure laterally adjacent the lead body, wherein the loop structure terminates at a free lead tip having a lead tip axis and is configured to position the lead tip laterally adjacent to the lead body such that the lead tip axis intersects the elongated longitudinal axis of the elongated lead body wherein the lead tip points towards the elongated longitudinal axis of the elongated lead body, the pacing lead further including at least one electrode on either the lead body or the fixation element, the loop structure presenting a predetermined width dimension greater than the diameter dimension of the coronary sinus, wherein the loop structure is configured to be laterally compressed by the wall of the coronary sinus to bias the free lead tip against the wall of the coronary sinus laterally adjacent to the lead body and to bias the at least one electrode against the wall of the coronary sinus.
4. The lead of
5. The lead of
6. The lead of
7. The lead of
8. The lead of
9. The lead of
10. The lead of
11. The lead of
12. The lead of
14. The lead of
15. The lead of
16. The lead of
17. The lead of
18. The lead of
19. The lead of
20. The lead of
|
This application is a continuation of U.S. patent application Ser. No. 11/358,644, entitled CORONARY SINUS LEAD FOR PACING THE LEFT ATRIUM, filed Feb. 21, 2006, which is a continuation-in-part of U.S. patent application Ser. No. 11/144,447, entitled CORONARY SINUS LEAD FOR PACING THE LEFT ATRIUM, filed Jun. 3, 2005, both of said applications hereby fully incorporated herein by reference.
The present invention relates generally to pacing leads. More particularly, the present invention relates to pacing leads for stable pacing of the left atrium through the coronary sinus.
Pacing to the left atrium is important for successful bi-atrial pacing. The pacing to the left atrium is usually accomplished by placing a pacing lead into the coronary sinus, which is a venous structure accessible through the right atrium of the heart and serves to drain the coronary veins. The coronary sinus is a curved, generally tubular structure typically having a lesser radius of curvature (the inner side of the curved tube) and a greater radius of curvature (the outer side of the curved tube). The coronary sinus is generally wider at its ostium and tapers inwardly away from the ostium towards the distal portions of the coronary sinus. The ostium of the coronary sinus is located at the juncture of the right atrium and the right ventricle.
To pace the left atrium, a pacing lead can be positioned so that an electrode contacts the wall of the coronary sinus closest to the left atrium. Because the coronary sinus is in electrical contact with the left atrium, by pacing the coronary sinus at this position, one can also pace the left atrium. The pacing lead generally is advanced to the ostium of the coronary sinus through the right atrium portion of the right heart. For effective pacing, electrodes on the pacing lead should be in constant electrical conductive contact with the wall of the coronary sinus, preferably the left atrial side of the coronary sinus. Conductivity is preferably sufficient so as to enable a pacing voltage of 3 volts or less.
To accomplish constant wall contact, different pacing lead configurations have been used to assist in the placement and retention of the pacing lead in the desired position. These prior leads, however, all have certain drawbacks making them not entirely satisfactory. For example, leads have been used in which a body of the lead is pre-formed to have a sinusoidal or helical configuration enabling the lead to expand into contact with the walls of the coronary sinus and retain the lead. Examples of such pre-formed coronary sinus leads are disclosed in U.S. Pat. No. 5,423,865 to Bowald et al. and U,S. Pat. No. 5,476,498 to Ayers. Such shapes, however, if not carefully sized to the diameter of the coronary sinus do not necessarily bias the electrodes against the wall of the coronary sinus with sufficient force to ensure good electrical connectivity resulting in instability and high pacing thresholds. Moreover, with helical shape leads, the electrodes may be difficult to properly position relative to the coronary sinus wall for optimal contact and thresholds.
Referring to
When the coronary sinus is wider than the pacing lead 20, the lead may assume a loop shape longitudinally disposed relative to proximal lead portion 21 as depicted in
Referring to
The present inventor has recognized that prior art leads and fixation methods provide a success rate of 60% or less when used to pace the left atrium via the coronary sinus. Hence, there is still a need for a lead and fixation method assuring stable pacing of the left atrium through the coronary sinus. Because the general problems discussed above have not been addressed by conventional pacing leads, there is a current need for pacing leads addressing the problems and deficiencies inherent with conventional designs.
The pacing lead of the various embodiments of the present invention substantially addresses the aforementioned problems of conventional designs by providing lead shapes and methods of pacing lead deployment that assure that the electrodes of the lead are firmly in electrical conductive contact with the wall of the coronary sinus so as to enable pacing voltages of 3 volts or less. In an embodiment, the improved pacing is accomplished because as the lead is advanced into the coronary sinus, a resilient fixation element preformed in a prolapsed position so as to be laterally adjacent the lead body, is laterally compressed by the walls of the coronary sinus as it is advanced into the coronary sinus. The resilience of the fixation element biases the lead body and portions of the fixation element against the wall of the coronary sinus, thereby improving electrical conductivity between the coronary sinus wall and electrodes disposed on the lead body or on the biased portions of the fixation element. In addition, in embodiments with a tip electrode, the prolapsed fixation element insures that the tip electrode is fixed relative to the coronary sinus closest to the left atrium, thus resulting in lower pacing voltages and thresholds and higher pacing stability.
In another embodiment, the lead has a pacing portion and a resilient fixation element extending distally from the pacing portion. The pacing portion includes a proximal electrode and a distal electrode. The fixation element is preformed so as to be doubled-back or prolapsed along the pacing portion, forming a loop structure. The width dimension of the preformed loop structure is predetermined so as to be larger than the diameter of the coronary sinus. When the loop structure is advanced into the coronary sinus, the loop is compressed in the width direction so that the electrodes of the pacing portion are biased against the wall of the coronary sinus by the resilience of the fixation element, thereby improving electrode conductive contact with the wall of the coronary sinus and resulting in improved stability and lower pacing and sensing thresholds. The electrodes of the pacing portion are biased against the wall of the coronary sinus (lesser curvature) where the left atrium is in proximity to the coronary sinus because the pacing lead proximal to the fixation element conforms naturally to the lesser curvature of the coronary sinus.
According to an embodiment, a pacing lead for implantation in a coronary sinus having an opening and a wall defining an interior and presenting a diameter dimension, includes an elongated lead body having a pacing portion with at least one electrode and a resilient fixation element. The fixation element extends from the pacing portion and defines a loop structure laterally adjacent the pacing portion. The loop structure presents a predetermined width dimension greater than the diameter dimension of the coronary sinus, wherein when the loop structure is advanced into the opening of the coronary sinus, the loop structure is laterally compressed by the wall of the coronary sinus and the at least one electrode is biased against the wall of the coronary sinus.
According to an embodiment of a method according to the invention, a pacing lead is provided having a lead body with a resilient fixation element extending from a distal end thereof. The resilient fixation element is preformed in a prolapsed configuration so as to form a loop laterally adjacent the lead body. According to the method, the prolapsed form of the fixation element is deployed with the lead positioned outside of the ostium of the coronary sinus. The fixation element is then advanced into the coronary sinus so that the loop structure of the fixation element is laterally compressed by the wall of the coronary sinus, thereby biasing electrodes on the lead body or fixation element against the wall of the coronary sinus.
A feature and advantage of an embodiment of the invention is that the left atrium can be paced by directing the tip electrode towards the left atrium side of the coronary sinus.
A feature and advantage of an embodiment of the invention is that assuring constant contact between the lead electrodes and the walls of the coronary sinus can increase the stability of the fixation and pacing.
A feature and advantage of an embodiment of the invention is that the design of the pacing lead enables use on various sized coronary sinuses without sacrificing stability or pacing/sensing thresholds.
A feature and advantage of an embodiment of the invention is a method of pacing lead deployment assuring constant contact between the lead electrodes and the walls of the coronary sinus.
A feature and advantage of an embodiment of the invention is that the left atrium can be paced by biasing one or more lead electrode against the wall of the coronary sinus using a resilient fixation element of the lead.
A feature and advantage of an embodiment of the invention is that the resilient fixation element of the lead may or may not contain electrodes for sensing and pacing the left atrium via the coronary sinus.
Referring to
The pacing lead 40 can also include one or more electrodes 58 disposed at any desired point on the proximal lead portion 42 or fixation element 43. The pacing lead 40 can further include a stylet 60 slidably disposed in the lead to initially straighten the preformed shape and which then may be withdrawn to the start of the fixation element to enable the preformed shape to develop and to selectively maintain the stiffness of the pacing lead 40 as the lead 40 is advanced into and positioned within the coronary sinus. It will also be appreciated that the shape of tip electrode 56 may be modified as desired, for example by maximizing contact surface area, to enable better contact with the wall of the coronary sinus and resultantly better performance.
The respective lengths of the first and second sections 48, 54 and the first and second angles 46, 52 between the first and second sections 48, 54 of the pacing lead 40 can be selected so that the tip electrode 56 will be in constant contact with the left atrial wall of the coronary sinus, i.e., to maximize contact between the tip electrode 46 and the left atrial wall of the coronary sinus. The overall length L and width W of the first and second sections 48, 54 can also be selected so that the tip electrode 56 will be in constant contact with the left atrial wall of the coronary sinus. The dimensions of the pacing lead according to exemplary embodiments of the present invention can be seen in Table I. Generally, the width of the pacing lead is preferably from about 10% to 200% greater than the diameter of the coronary sinus, more preferably from about 25% to about 75% greater than the diameter of the coronary sinus, and most preferably about 50% greater than the diameter of the coronary sinus for stability and good electrical contact.
TABLE I
Pacing lead dimensions according to various exemplary embodiments.
First Exemplary
Second Exemplary
Range
Embodiment
Embodiment
Lead Width
2 F to 9 F
5 F ± 1 F
5 F ± 1 F
(French)
Width - W (mm)
2.0 to 20.0
7.0 ± 5.0
7.0 ± 5.0
Length - L (mm)
5.0 to 60.0
30.0 ± 5.0
30.0 ± 5.0
First Section (mm)
2.0 to 30.0
10 ± 5.0
20.0 ± [10.0 cm]
Second Section
2.0 to 30.0
10 ± 5.0
20.0 ± [10.0 cm]
(mm)
First angle*
90-165
45 ± 5
45 ± 5
(degrees)
Second angle*
105-165
120 ± 30
120 ± 30
(degrees)
*Pre-formed angle prior to insertion into the coronary sinus.
While dimensions of the pacing lead 40 according to exemplary embodiments of the present invention are listed in Table I, one skilled in the art will recognize that changes may be made in form and detail of the dimensions without departing from the spirit and the scope of the invention. Therefore, the exemplary embodiments listed in Table I should be considered in all respects as illustrative and not restrictive.
Referring to
To implant the pacing lead 40 using a guiding catheter 62, one end of the guide wire 66 is first inserted deep into the coronary sinus. The other end of the guide wire 66 is operably coupled to the sheath 64 of the guiding catheter 62. The guide wire 66 can then maintain the positioning of the sheath 64 proximate the ostium of the coronary sinus.
Once the sheath 64 is held into place proximate the ostium of the coronary sinus, the stylet 60 of the pacing lead 40 is withdrawn out of the pacing lead 40 to a position proximate the first or proximal bend 44 of the pacing lead 40. The pacing lead 40 can then be advanced out of the sheath 64 to deploy the preformed loop of fixation element 43 while maintaining the stylet 60 at its position proximate the first bend 44 of the lead 40.
After the pacing lead 40 has been deployed out of the sheath 64 so that the lead 40 takes its pre-formed loop shape, the stylet 60 is kept at the first bend 44 of the pacing lead 40 while the lead 40 and stylet 60 are advanced into the coronary sinus, proximal bend 44 first. As stated above in Table I, in a first embodiment of the present invention, the first angle 46 between the first and second sections 48, 54, in its pre-formed configuration, is approximately 120 degrees.
As the pacing lead 40 is inserted into the ostium of the coronary sinus, the first angle 46 will compress or decrease until the tip electrode 56 comes into contact with the wall of the coronary sinus. Once this happens, the second angle 52 between the first and second sections 48, 54 will increase, e.g., to approximately one hundred and fifty degrees, due to compressive forces placed on the tip 56 as the pacing lead 40 progresses into the narrowing structure of the coronary sinus. In other words, in this wedged position, the walls of the coronary sinus flatten the distal curve 50 as the lead 40 is advanced into the tapering tubular structure of the coronary sinus. The tapering shape of the coronary sinus maximizes the contact between the tip electrode 56 and left atrium side of the coronary sinus.
By compressing the proximal and distal curves 44, 50, the lead 40 folds over and the tip electrode 56 is pressed against the left atrial side of the coronary sinus, thus improving the contact between the tip electrode 56 and the wall of the coronary sinus. Contact between the tip electrode 26 and the coronary sinus is maintained as the pacing lead 40 expands to assume its natural, expanded state. The contact results in lower pacing voltages and thresholds and higher pacing stability. The contact also inhibits any movement of the pacing lead 40 due to the heart beating and breathing of the patient once it is in its place within the coronary sinus. In this position, the coil or ring electrode 58 also has improved contact with the wall of the coronary sinus, as depicted in
In an alternative embodiments depicted in
As depicted in
In embodiments where proximal and distal portions 92, 94, are arcuate as depicted for example in
Central lumen 74 may terminate in pacing portion 68 as depicted in
The lateral biasing force exerted by the resilience of the fixation element is a function of the material properties, the cross-sectional dimension of the fixation element, and the amount of lateral deflection, annotated in the figures as ΔDfx of the fixation element. The amount of lateral deflection of the fixation element will vary depending on the diameter of the coronary sinus, and will generally be between about 0.5 centimeters and 12 centimeters, most typically from about 1.5 centimeters to about 6 centimeters. It will be appreciated that the magnitude of lateral biasing force may be predetermined by adjusting the material properties and dimensions of the fixation element using known principles of engineering. Generally, it is desirable if the fixation element provides between about 1 gram to about 30 grams of biasing force and more desirably between about 3 grams to about 10 grams when fixed in the coronary sinus.
Again, to implant the pacing lead 40 using a guiding catheter 62, one end of the guide wire 66 is first inserted deep into the coronary sinus as depicted in
Once the sheath 64 is held into place proximate the ostium of the coronary sinus, the stylet 60 of the pacing lead 40 is withdrawn to a position proximate the proximal portion 62 of pacing lead 40. The pacing lead 40 is then deployed out of the sheath 64. After the pacing lead 40 has been advanced out of the sheath 64 and any straightening member has been removed so that fixation element 70 takes its pre-formed loop shape with fixation element 70 in a prolapsed configuration laterally adjacent lead body 67, the lead 40 and stylet 60 are advanced into the coronary sinus, proximal portion 92 first as depicted in
It will be readily appreciated that, in addition to the embodiments disclosed above, a pacing lead according to the invention may take a variety of alternative forms, each including a fixation element prolapsed so as to form a loop structure laterally adjacent a body portion of the lead. For the purposes of the present invention, the term loop structure includes any lead wherein the lead tip 57a, 102, is doubled back along the lead body and a longitudinal axis extending from the lead tip 57a, 102, parallels or intersects a longitudinal axis of the lead body when the tip and lead body axes are projected onto a common plane parallel to and including the lead body axis. For instance, the fixation element forming a loop structure may include a plurality of more or less straight segments angled with respect to each other, or a plurality of curved segments of various radii, a single segment with a more or less continuous curve, or a plurality of straight and curved segments joined together. The fixation element and lead body may be made with any material having suitable engineering and biocompatibility properties. The lead electrodes may take any suitable form including without limitation, coils or rings, and “buttons” or protuberances, and may be positioned on the lead body or the fixation element or any combination thereof. It may be relatively more desirable, however, to locate the electrodes proximal to any relatively sharp angles or bends in the lead so as to avoid fractures in the conductors leading to the electrodes.
While insertion of the pacing lead into the coronary sinus has been depicted and described as being done by deploying the lead outside the ostium of the coronary sinus so that lead takes its pre-formed shape before it is advanced into the coronary sinus, in other embodiments, such as where the coronary sinus has a smaller diameter, the pacing lead can be introduced tip-first in the coronary sinus in the conventional fashion.
Although the present invention has been described with reference to particular embodiments, one skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and the scope of the invention. Therefore, the illustrated embodiments should be considered in all respects as illustrative and not restrictive.
Patent | Priority | Assignee | Title |
10456581, | Nov 20 2015 | Cardiac Pacemakers, Inc | Single pass coronary venous lead for multiple chamber sense and pace |
10603488, | Feb 10 2017 | Oscor Inc. | Implantable medical devices having diamagnetic conductors and contacts |
11446510, | Mar 29 2019 | Cardiac Pacemakers, Inc. | Systems and methods for treating cardiac arrhythmias |
11510697, | Sep 11 2019 | Cardiac Pacemakers, Inc. | Tools and systems for implanting and/or retrieving a leadless cardiac pacing device with helix fixation |
11571582, | Sep 11 2019 | Cardiac Pacemakers, Inc. | Tools and systems for implanting and/or retrieving a leadless cardiac pacing device with helix fixation |
11833349, | Mar 29 2019 | Cardiac Pacemakers, Inc. | Systems and methods for treating cardiac arrhythmias |
Patent | Priority | Assignee | Title |
4154247, | Apr 01 1977 | Medtronic, Inc. | Formable cardiac pacer lead and method of assembly and attachment to a body organ |
5879295, | Apr 02 1997 | Medtronic, Inc | Enhanced contact steerable bowing electrode catheter assembly |
6096036, | May 05 1998 | Cardiac Pacemakers, Inc | Steerable catheter with preformed distal shape and method for use |
Executed on | Assignor | Assignee | Conveyance | Frame | Reel | Doc |
Mar 05 2009 | Oscor Inc. | (assignment on the face of the patent) | / | |||
Jan 21 2010 | WORLEY, SETH | Oscor Inc | ASSIGNMENT OF ASSIGNORS INTEREST SEE DOCUMENT FOR DETAILS | 023889 | /0628 | |
Jan 24 2022 | Oscor Inc | WELLS FARGO BANK, NATIONAL ASSOCIATION, AS ADMINISTRATIVE AGENT | SECURITY INTEREST SEE DOCUMENT FOR DETAILS | 058838 | /0203 |
Date | Maintenance Fee Events |
Feb 26 2016 | REM: Maintenance Fee Reminder Mailed. |
Mar 08 2016 | M2551: Payment of Maintenance Fee, 4th Yr, Small Entity. |
Mar 08 2016 | M2554: Surcharge for late Payment, Small Entity. |
Mar 09 2020 | REM: Maintenance Fee Reminder Mailed. |
Mar 17 2020 | M2552: Payment of Maintenance Fee, 8th Yr, Small Entity. |
Mar 17 2020 | M2555: 7.5 yr surcharge - late pmt w/in 6 mo, Small Entity. |
Aug 26 2022 | BIG: Entity status set to Undiscounted (note the period is included in the code). |
Jan 03 2024 | M1553: Payment of Maintenance Fee, 12th Year, Large Entity. |
Date | Maintenance Schedule |
Jul 17 2015 | 4 years fee payment window open |
Jan 17 2016 | 6 months grace period start (w surcharge) |
Jul 17 2016 | patent expiry (for year 4) |
Jul 17 2018 | 2 years to revive unintentionally abandoned end. (for year 4) |
Jul 17 2019 | 8 years fee payment window open |
Jan 17 2020 | 6 months grace period start (w surcharge) |
Jul 17 2020 | patent expiry (for year 8) |
Jul 17 2022 | 2 years to revive unintentionally abandoned end. (for year 8) |
Jul 17 2023 | 12 years fee payment window open |
Jan 17 2024 | 6 months grace period start (w surcharge) |
Jul 17 2024 | patent expiry (for year 12) |
Jul 17 2026 | 2 years to revive unintentionally abandoned end. (for year 12) |